1971 240z brake booster swap?

[Jimmy Z]

I'm resurrecting a '71 240z, and discovered that the can on my brake booster has significant rust issues on the lower rear exterior. In search of a replacement booster, I'm finding that the early ('70-'71) rebuilt/reconditioned options are not available. I ordered one from the local parts store, and although the photo in their system was identical to mine, there are differences in the piece the supplier sent. The store manager did some searching and found that the one in the photo is not available. I checked with a few other suppliers and ran into the same issue. My question is, will a '73 240z booster work in my car? The can shape and dimensions are the same as mine, the only noticeable difference between the two units is that the rod  that connects to the pedal on the early model has a smaller diameter shaft, and a clevis. The '73 booster has a larger (10m) thread with a nut, no clevis connector. It looks like the swap would work, and it would be easy to fab a connector for the larger rod, but I'd like some reassurance that the unit will work once I take the leap. There's a booster rebuild shop in my area, and I'm going to find out tomorrow if they can save my unit, but given the condition of the can, I'm not optimistic. Attached are a couple of photo's of the original booster.

[Patcon]

I think you will find your booster is salvageable. It really doesn't look that heavily corroded. I would prefer to have a booster shop rebuild the unit, because of the less than stellar work that is often found in reman boosters and dealing with a local business. If you have them do it and they do a good job. Post them up for others to support them.

[Namerow]

I agree that your unit looks quite restorable.  CZCC member 240260280Z (previously known as Blue) has a posting somewhere that shows a detailed teardown and repair of one of these units.  He used RTV sealant to repair the damaged internal vacuum liner.  That liner is, I suspect, unobtainium as a separate service part (contact Courtesy Nissan to confirm), so a local brake rebuild shop is probably going to have to patch yours, rather than replace it.

There is now another way to go about this, though.  Motorsport Auto have begun to offer an 8" mastervac unit for use in 70-71-72 Z's...

http://www.thezstore.com/page/TZS/PROD/classic01a/24-5760

They say: "This unit is designed to bolt directly in place of the 70-72 master vac while working with the original master cylinder (not included). In fact, no modifications are required to run this booster beyond removing the old unit."

Not inexpensive at $325, but probably good value for the money, all things considered.  Only an expert would notice the difference in canister size.

[Jimmy Z]

Thank you Patcon and Namerow for your quick response. I agree that a rebuild of the original unit would be the preferred solution, and I certainly appreciate your confidence that mine is salvageable. I also agree that anytime you resort to a "re-manufactured" item, it's a crap shoot. The shop where I'm taking the booster was recommended by a fellow z enthusiast, so this challenge is nothing new to them and I hope they can handle mine. I also saw the Z Store option, but as usual with these projects, there are budget considerations, and spending $325 + on the booster will be an impact that I had not considered in my build plan, and I'd prefer to avoid if possible.  The car is now at the beauty spa getting a complete body massage and face lift (speaking of budget impacts!), so I have time to resolve this before I get the car back and start the re-assembly. I'll let you know how it goes with the rebuild shop, and keep you posted on my progress.

Thanks again for taking the time to share your thoughts.

[Patcon]

6 hours ago, Namerow said:

/I agree that your unit looks quite restorable.  CZCC member 240260280Z (previously known as Blue) has a posting somewhere that shows a detailed teardown and repair of one of these units.  He used RTV sealant to repair the damaged internal vacuum liner.  That liner is, I suspect, unobtainium as a separate service part (contact Courtesy Nissan to confirm), so a local brake rebuild shop is probably going to have to patch yours, rather than replace it.

I googled the part number off a diaphragm out of a booster. I found a source for them but they had a minimum order of like 1000. I don't think rebuilders are patching up booster parts. I believe booster rebuilders have sources for these parts that we don't have...

[S30Driver]

Another booster option...        https://zcardepot.com/power-brake-booster-7-240z-70-73-new.html

[Namerow]

11 hours ago, Patcon said:

I googled the part number off a diaphragm out of a booster. I found a source for them but they had a minimum order of like 1000. I don't think rebuilders are patching up booster parts. I believe booster rebuilders have sources for these parts that we don't have...

Interesting find.  It never occurred to me that there would be supplier(s) out there whose sole target market is the rebuild industry.  I was thinking more along the lines of a local shop doing a customer a favor, rather than a full-on parts rebuilder.  Maybe Steve/nix240 will get interested and cast up his own version of replacement .

[Patcon]

12 hours ago, Namerow said:

Interesting find.  It never occurred to me that there would be supplier(s) out there whose sole target market is the rebuild industry.  I was thinking more along the lines of a local shop doing a customer a favor, rather than a full-on parts rebuilder.  Maybe Steve/nix240 will get interested and cast up his own version of replacement .

Steve and I have talked about it. He doesn't want to produce parts that could have significant liability attached to them

[Captain Obvious]

Can't say I blame him.

I wouldn't want to produce and sell something for brakes, or seatbelts, or anything that held a wheel on.

[Jimmy Z]

Brake booster update. I dropped the booster at the repair/rebuild shop yesterday (Mon.). They are obviously a large player in a niche business. They supply new, and rebuild all types of car and commercial/industrial vehicle brake boosters, compressors and various related bits and pieces. There were no concerns on the part of the proprietor about the condition of the can, or rebuilding the unit. Easy deal. The rebuild should be compete by Thurs. (four work days). Once I retrieve the part, I'll follow up with my impression of the work and a couple of "after" photo's. If all's well, and at this point I have a high level of confidence it will be, I'll post the shops contact info, and the cost for my rebuild.

Thanks again to all for your input.

[kunzma]

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Edited May 9, 2019 by kunzma
add quote

[kunzma]

On 5/15/2018 at 9:58 AM, Jimmy Z said:

Brake booster update. I dropped the booster at the repair/rebuild shop yesterday (Mon.). They are obviously a large player in a niche business. They supply new, and rebuild all types of car and commercial/industrial vehicle brake boosters, compressors and various related bits and pieces. There were no concerns on the part of the proprietor about the condition of the can, or rebuilding the unit. Easy deal. The rebuild should be compete by Thurs. (four work days). Once I retrieve the part, I'll follow up with my impression of the work and a couple of "after" photo's. If all's well, and at this point I have a high level of confidence it will be, I'll post the shops contact info, and the cost for my rebuild.

Thanks again to all for your input.

How did this turn out?